package com.aiton.administrator.shane_library.shane.utils;

import java.math.BigDecimal;
import java.text.DecimalFormat;

public class Arith {  
private static final int DEF_DIV_SCALE = 10;
   //保留2位小数

   /**
    * 保留2位小数
    * @param a
    * @return
     */
   public static double get2Double(double a){
      DecimalFormat df=new DecimalFormat("0.00");
      return new Double(df.format(a).toString());
   }
   /**
* * 两个Double数相加 * 
*  
* @param v1 * 
* @param v2 * 
* @return Double 
*/  
public static Double add(Double v1, Double v2) {  
   BigDecimal b1 = new BigDecimal(v1.toString());  
   BigDecimal b2 = new BigDecimal(v2.toString());  
   return new Double(b1.add(b2).doubleValue());  
}  
  
/** 
* * 两个Double数相减 * 
*  
* @param v1 * 
* @param v2 * 
* @return Double 
*/  
public static Double sub(Double v1, Double v2) {  
   BigDecimal b1 = new BigDecimal(v1.toString());  
   BigDecimal b2 = new BigDecimal(v2.toString());  
   return new Double(b1.subtract(b2).doubleValue());  
}  
  
/** 
* * 两个Double数相乘 * 
*  
* @param v1 * 
* @param v2 * 
* @return Double 
*/  
public static Double mul(Double v1, Double v2) {  
   BigDecimal b1 = new BigDecimal(v1.toString());  
   BigDecimal b2 = new BigDecimal(v2.toString());  
   return new Double(b1.multiply(b2).doubleValue());  
}  
  
/** 
* * 两个Double数相除 * 
*  
* @param v1 * 
* @param v2 * 
* @return Double 
*/  
public static Double div(Double v1, Double v2) {  
   BigDecimal b1 = new BigDecimal(v1.toString());  
   BigDecimal b2 = new BigDecimal(v2.toString());  
   return new Double(b1.divide(b2, DEF_DIV_SCALE, BigDecimal.ROUND_HALF_UP)  
     .doubleValue());  
}  
  
/** 
* * 两个Double数相除，并保留scale位小数 * 
*  
* @param v1 * 
* @param v2 * 
* @param scale * 
* @return Double 
*/  
public static Double div(Double v1, Double v2, int scale) {  
   if (scale < 0) {  
    throw new IllegalArgumentException(  
      "The scale must be a positive integer or zero");  
   }  
   BigDecimal b1 = new BigDecimal(v1.toString());  
   BigDecimal b2 = new BigDecimal(v2.toString());  
   return new Double(b1.divide(b2, scale, BigDecimal.ROUND_HALF_UP).doubleValue());  
}  
}  